Freidel–Crafts alkylation of benzene with an alcohol:

Treatment of the alkene along with the acid leads to a carbocation that can then react with an aromatic ring by similar electrophilic substitution mechanism already explained. As far as the alkene is concerned, this is other instance of electrophilic addition in which a proton is attached to one end of the double bond and a phenyl group is added to another.

Figure: Friedel-Crafts alkylation of benzene with an alkene.

Friedel-Crafts reactions can also be performed with alcohols in the existence of mineral acid. The acid leads to the removal of water from the alcohol resultant in the creation of an alkene that can then be converted to a carbocation as already explained.

Figure:  Freidel-Crafts alkylation of benzene with an alcohol.